2004 INFINITI QX56 transfer motor

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
TF-57
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Revision: August 20072004 QX56
30Power supply for A/D
converter &Ignition key is set to ON position. 4.5 - 5.5V
Ignition key is set to OFF position. 0V
31Transfer fluid tempera-
ture sensor &At 20°C (68°F) 1.1V
At 80°C (176°F) 0.3V
33 Transfer shift relay (High)
&While actuator is operating from “4H”
to “4LO”Battery voltage
Actuator does not operate. 0V
34 Clutch pressure switch4WD shift switch is set to AUTO or
4H, then A/T selector lever is set to D
position. (wait detection system:
OFF)Battery voltage
4WD shift switch is set to 2WD,
AUTO or 4H, then A/T selector lever
is set to D position. (wait detection
system: ON)0V
35 Line pressure switch4WD shift switch is set to 2WD,
AUTO or 4H, then A/T selector lever
is set to D position.Battery voltage
—0V
36 CONSULT-II (RX) — — —
40 ATP switch
&A/T selector lever is set to P position. Battery voltage
A/T selector lever is set to any posi-
tion other than P.Less than 1V
41Transfer motor relay
monitorTransfer motor relay is ON. Battery voltage
Transfer motor relay is OFF. Less than 1V
42Transfer shift relay
(LOW)While actuator is operating from
“4LO” to “4H” positionBattery voltage
Actuator does not operate. 0V
43 Wait detection switch4WD shift switch is set to any posi-
tion other than 4LO.Battery voltage
4WD shift switch is set to 4LO posi-
tion.*3Less than 1V
44Transfer 4LO actuator
switch4WD shift switch is set to any posi-
tion other than 4LO. (Actuator: High
position)Battery voltage
4WD shift switch is set to 4LO posi-
tion. (Actuator: Low position)Less than 1V
45 Ground — — — Te r m i n a l
No.Item ConditionJudgement standard
(Approx.)

TF-64
TRANSFER MOTOR AND TRANSFER MOTOR RELAY
Revision: August 20072004 QX56
TRANSFER MOTOR AND TRANSFER MOTOR RELAYPFP:00000
Diagnostic ProcedureEDS00185
1. CHECK TRANSFER MOTOR AND TRANSFER MOTOR RELAY
Refer to TF-96, "
TRANSFER MOTOR" and TF-97, "TRANSFER
MOTOR RELAY" .
OK or NG
OK >> GO TO 2.
NG >> Replace transfer motor or transfer motor relay.
2. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “MAIN SIGNALS” in Data Monitor.
2. Read out ON/OFF status of “MOTOR RELAY”.
3. When the value is different from standard value although ON/
OFF switching occurs, check the following items.

PNP switch and throttle position sensor circuits
Refer to AT-109, "
DTC P0705 PARK/NEUTRAL POSITION
SWITCH" , AT-129, "DTC P1705 THROTTLE POSITION SEN-
SOR" .
OK or NG
OK >> GO TO 3.
NG >> 1. Perform transfer control unit input/output signal
inspection. Refer to TF-55, "
TRANSFER CONTROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector.
3. CHECK TRANSFER MOTOR RELAY POWER SOURCE
1. Disconnect transfer motor relay harness connectors E153 and
E154.
2. Turn ignition switch to ON position.
3. Check voltage between transfer motor relay harness connector
E153 terminal 5 (G/R), E154 terminal 2 (Y/R), and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following.

No. 58 fuse (20A)

No. 49 fuse (10A)

Harness continuity between ignition switch and No. 58 fuse (20A) and No. 49 fuse (10A).

Harness continuity between fuse and transfer motor relay.
LDIA0102E
SMT975D
Voltage : Battery voltage
LDIA0070E

TRANSFER MOTOR AND TRANSFER MOTOR RELAY
TF-65
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Revision: August 20072004 QX56
4. CHECK HARNESS CONTINUITY
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connectors E142 and
E143, and transfer motor harness conector F57.
3. Check continuity between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connector.
5. PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" or TF-31, "Trouble Diagnosis with CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit input/output signal inspection. Refer to TF-55, "
TRANSFER CON-
TROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector. Connec-
torTe r m i n a l
(Wire
color)Connec-
torTe r m i na l
(Wire
color)Continu-
ity
F57 14 (R)
E143 41 (R)
Yes E153 3 (R)
E154 1 (LG) E142 14 (LG)
Ground — F57 15 (B)
LDIA0071E

TF-94
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
Symptom 9. 4WD System Does Not Operate (The Vehicle Cannot Be Put Into
4WD Mode-Hydraulic System Failure)
EDS0018M
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Put A/T selector lever in D.
3. Turn 4WD shift switch to 4H and back to 2WD while reading out
ON/OFF status of "CL PRES SW".
Without CONSULT-II
Check voltage between transfer control unit harness connector E143
terminal 34 (BR) and ground.
Refer to TF-55, "
TRANSFER CONTROL UNIT INSPECTION
TABLE" .
OK or NG
OK >> 1. Check transfer fluid level.
2. Disassemble transfer unit and check the following.
–Transfer motor
–Main oil pump assembly
–Sub-oil pump assembly
–Oil strainer
–Control valve assembly
–2-4WD shift solenoid valve
–Oil filter element
–Lip seal
–Strainer O-ring
–Main oil pump drive gear
–Seal ring
–D-ring
–Clutch piston
–Clutch assembly
NG >> GO TO 2.
2. CHECK CLUTCH PRESSURE CIRCUIT
Check clutch pressure switch circuit.
Refer to TF-72, "
Diagnostic Procedure" .
OK or NG
OK >> GO TO 3.
NG >> Check, repair or replace faulty parts.
3. CHECK PROCEDURES FROM THE BEGINNING
Check again.
OK or NG
OK >> Inspection End.
NG >> Recheck each connector pin terminals for damage or loose connection.
WDIA0087E

TROUBLE DIAGNOSES FOR SYMPTOMS
TF-95
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Revision: August 20072004 QX56
Component InspectionEDS0018N
4WD SHIFT SWITCH
Check continuity between each terminal.
2-4WD SHIFT SOLENOID VALVE AND TRANSFER FLUID TEMPERATURE SENSOR
Measure resistance between terminals of transfer terminal cord
assembly harness connector F56.
4WD SOLENOID VALVE, CLUTCH PRESSURE SWITCH AND LINE PRESSURE SWITCH
Measure resistance between terminals of transfer terminal cord
assembly harness connector F56.
Terminals Switch position Continuity
1 - 22WD Yes
Except 2WD No
1 - 3, 1 - 4AUTO Yes
Except AUTO No
1 - 4, 1 - 54H Yes
Except 4H No
1 - 4, 1 - 64LO Yes
Except 4LO No
WDIA0090E
Component parts TerminalsResistance
(Approx.)
2-4WD shift solenoid valve 4 - 520°C (68°F):
22.8 - 25.2Ω
Transfer fluid temperature
sensor2 - 320°C (68°F): 2.5 kΩ
80°C (176°F): 0.3 kΩ
LDIA0093E
Component
partsTerminals Remarks
4WD sole-
noid valve6
Ground
terminalApprox. 20°C (68°F): Approx. 3.0 - 3.4Ω
Clutch pres-
sure switch7In room temperature

2-4WD shift solenoid valve “OFF”: No conti-
nuity

2-4WD shift solenoid valve and transfer
motor “ON”: Continuity exists
Line pressure
switch1In room temperature

Turn ignition switch to “OFF” position and
leave vehicle for more than 5 minutes.
(OFF): No continuity

Transfer motor “ON”: Continuity exists
LDIA0094E

TF-96
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
TRANSFER DROPPING RESISTOR
Check resistance between terminals.
ATP SWITCH, NEUTRAL-4LO SWITCH AND WAIT DETECTION SWITCH
1. Remove the ATP switch, neutral-4LO switch and the wait detection switch.
2. Measure the resistance between terminals of ATP switch F55, neutral-4LO switch F60 , and wait detection
switch F59.
TRANSFER MOTOR
Apply battery voltage directly to transfer motor harness connector
F57. (Positive: Terminal 14, Negative: Terminal 15)
Transfer motor should operate.
WDIA0091E
Resistance : 11.2 - 12.8 Ω
Switch released state : Continuity should not
exist
Switch pushed state : Continuity should exist
WDIA0082E
LDIA0097E

TROUBLE DIAGNOSES FOR SYMPTOMS
TF-97
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Revision: August 20072004 QX56
TRANSFER MOTOR RELAY
1. Apply battery voltage and ground directly to transfer motor relay
E154 terminals 1 and 2.
2. Check continuity between transfer motor relay E153 terminals 3
and 5.
TRANSFER SHIFT RELAY (HIGH & LOW)
Check continuity between transfer shift high relay E46 and low relay
E47 terminals 3 and 4.
ACTUATOR AND ACTUATOR POSITION SWITCH
Actuator
Operation and resistance check

Apply battery voltage directly to actuator assembly.
Actuator Position Switch
Continuity check
Condition Continuity (3-5)
Battery voltage is applied Yes
No voltage is applied No
LDIA0098E
Condition Continuity
12V direct current supply
between terminals 1 and 2No
No current supply Yes
LDIA0099E
Operating check Battery positive terminal Battery negative terminal
121 24
224 21
Check Approx. 0.2Ω (When the motor is not operated.)
LDIA0100E
Continuity checkBattery positive
terminalBattery negative
terminalContinuity
121 24 20 - 22
224 21 23 - 22
LDIA0101E

AIR BREATHER HOSE
TF-105
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Revision: August 20072004 QX56
AIR BREATHER HOSEPFP:31098
Removal and InstallationEDS00319
Refer to the figure for air breather hose removal and installation information.
CAUTION:

Make sure there are no pinched or restricted areas on the air breather hose caused by bending or
winding when installing it.

Install the air breather hose into the air breather (metal connector) and actuator (case connector)
until the hose end reaches the base of the tube.

Install the air breather hose into the breather tube (metal connector) and transfer motor (case con-
nector) until the hose end reaches the end of the curved section.
SDIA2656E